Whoa… slow down there chippy.
Does the vehicle have clear flood mode?
Suggest you research that.
Next, before diving in to replace a head gasket you should do a compression test on all cylinders ( assuming you only did a single cylinder)
Also perform a leak down test on each cylinder ( you tube videos available to explain the results )
Beyond just replacing the head gasket both the head and block would need to be checked for flatness also inspected for possible cracks.